This invention relates to a rotary cutting tool, and more particularly to a rotary cutting tool in which at least two of the cutting blades thereof have one or more smooth segments and one or more serrated segments. The milling cutter described herein may be utilized in either an end cutting or side cutting operation.
Milling cutters known in the prior art have been capable of providing either a rapid cutting capability ("roughing cutters") or a close dimensional smooth surface finish ("finishing cutters"); however, so far as applicant is aware, none of the commercially available cutters is capable of providing both rapid cutting and smooth, close dimensional finish qualities simultaneously and satisfactorily. Roughing cutters known in the art produce such deep grooves and gouges in the workpiece that a machinist cannot "work to a line" (dimension). As a result, a tool change or adjustment usually is necessary to hold dimensional tolerance and produce the desired surface finish, if the milling job is to be completed within a reasonable period of time.
It is well known that the addition of chip-breaking cutting teeth upon the blades of a rotary cutting tool will improve the cutting speed of the tool, but will leave scratches, gouges and grooves in the workpiece. The use of smooth blades produces a more uniform, polished surface finish, but at the cost of higher energy consumption and reduced cutting speed. It is the object of this invention to provide a milling cutter which combines the desirable qualities of smooth and serrated cutting blades so as to produce, in a short production time and without the necessity of a tool change, a work piece milled to the desired tolerance at the finish line and exhibiting a satisfactory surface finish.